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TI Simplifies Audio/Video Synchronization with Cost-Effective, Single-Chip Digital Audio Delay
New Digital Audio Delay Minimizes Board Space and Provides Easily Configurable Lip Sync Delay with 170 ms per Channel
Audio/video (A/V) synchronization issues arise because video processing is more intensive than audio processing. As a result, audio is ready for playback before the video. Without synchronization, what viewers hear will not match what they see on the screen -- where the timing of lips moving is off from the words being heard, for example -- significantly impacting the overall viewing experience. Also known as "lip sync," A/V synchronization is maintained by delaying playback of the audio stream, until the video stream has finished processing. The actual delay required for synchronization depends upon the type of A/V signals and the current video mode.
Synchronization also plays a role in wireless multi-channel speaker applications. Given the inherent processing delays of wireless transmission, it takes more time for transmitted channels than non-transmitted channels to output audio. The non-transmitted channels, therefore, must have additional delay to synchronize them with the transmitted channels.
“As TV applications are getting more sophisticated and more wireless components are being adopted, there is a real need in the market for lip sync devices that can be easily implemented and meet the needs of manufacturers,” says Kevin Belnap, marketing manager for Home Audio, Texas Instruments. “The TPA5050 digital audio delay is practically a drop-in device that provides lip sync delay in the most cost-effective and compact manner.”
With the introduction of the TPA5050 digital audio delay, TI offers developers a cost-effective way to implement lip sync delay in a single chip that is easily configured and reduces system complexity, which will ultimately provide consumers an even better end product when purchasing newer TV technologies, including DLP(R) HDTVs. Additionally, given the tight physical constraints of A/V applications such as LCD TVs, minimizing the size of components on the printed circuit board (PCB) is an important design consideration.
Because the new chip can provide up to 170 milliseconds (ms) of delay per channel--and with resolution down to a single sample--the TPA5050 digital audio delay can make the audio and video delay imperceptible. With 170 ms of delay per channel, the TPA5050 digital audio delay can synchronize the most demanding TV applications. Its integrated architecture and 4mm x 4mm QFN package minimizes board footprint.
In addition to minimizing cost, board space and configuration complexity, the TPA5050 digital audio delay will automatically clear the delay memory during a delay time change, eliminating undesirable pops and clicks. The TPA5050 digital audio delay supports 16 to 24 bit data, sample rates from 32 to 192 kHz, and all standard audio configuration interfaces, including I2S,
Left- and Right-Justified. All internal clocking on the TPA5050 digital audio delay is generated from the bit clock so no crystal or oscillator is needed. The inputs are 5 Volts tolerant so interfacing with a host of microcontrollers and audio processors is not an issue. Developers requiring longer delays for professional or specialized applications can cascade multiple TPA5050 chips.
The TPA5050 complements other TI digital and analog products that support audio applications, such as Class D amplifiers, audio converters, processors and switch mode power management.
Availability, Packaging, and Pricing
Available now in production volumes, the TPA5050 digital audio delay costs $3.20 each in 1,000 unit quantities.
Two other members of the TPA505x family are currently sampling. The TPA5051 digital audio delay offers support for four channels with up to 85 ms lip sync delay per channel. The TPA5052 digital audio delay is controlled through five mode pins, providing 32 programmable delay settings ranging from zero to 170 ms and is otherwise pin-for-pin compatible with the TPA5050. The mode pins eliminate the need to manually configure delay length at power on.
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